"And so my fellow Americans, ask not what your country can do for you;
but what you can do to co-opt with interstellar agents in order to
prevent my impending assassination."

That was the quote, right? Local author Michael J. Foy's most recent novel, The Kennedy Effect,
lays out this beyond-loony tale, in which a parallel earth witnesses
President Kennedy's assassination here on our planet, leaving the
powers that be -- the Agency -- to ponder whether or not they must stop
their own version of JFK from being killed in a scenario that could
cause the destruction of both universes through a big bang.